A critical step in the development of any machine with moving components is to validate the minimum clearance between these moving components during operation of the machine. This validation is typically accomplished by installing solid, metal rub pins which make physical contact with components during operation. After the machine is shut down, the rub pins are inspected and measured to determine the amount of wear to the pins. This inspection may require disassembly of the machine. The amount of wear on the rub pins indicates the minimum clearance that occurred at some point during the operation of the machine.
There remains a need for a device which can accurately indicate when a predetermined clearance between two surfaces is reached in real-time during the operation of a machine.